1. Field of the Invention
This invention relates to medical devices such as catheters and catheter assemblies for use in medical procedures. More specifically, this invention relates to catheter systems, such as the kind used in percutaneous transluminal coronary angioplasty (PTCA) procedures, as well as the kind used in cryoplasty and/or cooling procedures.
2. Description of the Related Art
Percutaneous transluminal coronary angioplasty (PTCA) is a procedure which is well established for the treatment of blockages, lesions, stenosis, thrombus, etc. present in body lumens such as the coronary arteries and/or other vessels.
A widely used form of percutaneous coronary angioplasty makes use of a dilatation balloon catheter which is introduced into and advanced through a lumen or body vessel until the distal end thereof is at a desired location in the vasculature. Once in position across a afflicted site, the expandable portion of the catheter, or balloon, is inflated to a predetermined size with a fluid at relatively high pressures. By doing so the vessel is dilated, thereby radially compressing the atherosclerotic plaque of any lesion present against the inside of the artery wall, and/or otherwise treating the afflicted area of the vessel. The balloon is then deflated to a small profile so that the dilatation catheter may be withdrawn from the patient's vasculature and blood flow resumed through the dilated artery.
It is known that in some angioplasty procedures, the reopening of a vessel is in whole or in-part frustrated by complete or partial reclosure of the artery or vessel. Often the mechanism responsible for the closure of the vessel is vessel recoil and/or more commonly restenosis of the lesion resulting from continued growth of the lesion back into the vessel.
In angioplasty procedures of the kind described above, there may be restenosis of the artery, which either necessitates another angioplasty procedure, a surgical by-pass operation, or some method of repairing or strengthening the area. To reduce restenosis and strengthen the area, a physician can implant an intravascular prosthesis for maintaining vascular patency, such as a stent, inside the artery at the lesion.
In some cases, where the vessel and/or surrounding tissue has had its blood flow blocked or reduced, it has been shown that by cooling the tissue the amount of necrosis is reduced if re-profusion is established within a given treatment window. However current catheter systems do not adequately provide both a mechanism for establishing re-profusion and providing a cooling effect within the desired window.
All US patents and applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.